In Google Analytics have a very useful option but is somewhat hidden and you might not know, this is the log. Such marks may help you to check traffic increases or decreases at a certain time or to check off a series of events on your panel reports.
How do I log in Analytics?
Very simple, just in the drawing views, you know in the Public / General Vision, under days a down arrow appears that if we click a row it opens and in the right area we will have the choice to create an entry with this text: + Create a new annotation.
Once you prick a form in which we have to mark the day in which we review that note, a field for the description, which is limited to 160 characters and finally opens a field to set the public record as if we want others to see users with access to private panel or if that information will display only us.
Why do we serve the annotations?
With it we can see that causes have led to significant increases in traffic on a particular day for campaigns or other actions we have created, for example if one day we launched an Adwords campaign or email marketing and triggered by traffic, one annotation in this pane, serves as a reminder, since a simple click on the icon that is generated below the day we will be able to check by observation that registered, what caused that peak or drop in our web traffic.